1. Field of the Invention
The present invention relates to a spring device, in particular for a secondary suspension device of a rail vehicle, comprising a spring body substantially made of a polymeric material and defining an axial direction and a radial direction. The spring body, in the axial direction, has a central section located between a first and section terminating in a first outer end surface and a second end section terminating in a second outer end surface. The central section has at least one radially waisted section, while the first end section has a recess extending, in the axial direction, from the first outer end surface towards the central section such that an axial spring body cavity is formed, the axial spring body cavity being confined by a compliant inner surface. The invention further relates to a running gear comprising such a spring device.
2. Description of Related Art
Such spring devices well known in the art and used, for example, as a part of a secondary suspension device as shown in EP 0 337 135 B1 (the entire disclosure of which is incorporated herein by reference). Typically, the axial spring body cavity is used to mount and center the spring body to the running gear and the wagon body unit (e.g. the wagon body itself or a bolster connected to the wagon body). Obviously, the generally hourglass shaped design of the spring body as shown in EP 0 337 135 B1 has to be adapted to the specific rail vehicle. In particular, its axial rigidity (i.e. the rigidity along the central spring body axis) as well as its transverse rigidity (i.e. the rigidity transverse to the central spring body axis) has to be tuned to the specific vehicle is used in.
This has the disadvantage that, typically, for every single vehicle type a separate spring design has to be developed and tested, which renders the design of the secondary suspension comparatively time-consuming and expensive.